Jun 122020
 

The Perseverance dredger, tug and mud barges working near Barley Mow, 1980

If you leave the canal towpath and walk over the old road bridge at Fleet’s Pondtail you will come across a large plaque mounted on the bridge’s railing which is dedicated to the steam dredger ‘Perseverance’ and its volunteer crews who completed the dredging of the canal at the bridge in 1993. So what was Perseverance, who were the volunteers and what did the craft do to deserve commemoration?

The Craft’s Story

Steam Dredger Perseverance was built by Grafton Cranes Ltd of Bedford, who subcontracted the construction of the hull and pontoons to James Pollock & Son based on the River Thames at Millwall, having been commissioned by the Grand Union Canal Company in 1934. Registered as No. 14 in the GUCC, she was believed to have worked on the modernisation of the Grand Union during the 1930s. With the nationalisation of the canal network in 1948, ownership passed to the British Transport Commission then to the British Waterways board; she had a major overhaul in the 1950s when the boiler was replaced with one from a Luton laundry company, before being bought by the Kennet and Avon Canal trust in 1967.

The dredger was then purchased by the Surrey and Hants Canal Society (now the Basingstoke Canal Society) for £225 in 1973, but was in need of an extensive overhaul, including renewing the boiler tubes. Lying near County Lock in Reading, Perseverance was completely overhauled by the SHCS volunteers, not forgetting the Army who gave a great deal of assistance. After a successful boiler examination and certification the dredger was dismantled – with her now working crane used to help move some of the heavy parts – and the whole caboodle was moved to Odiham by road courtesy of Watney’s brewery. Reassembled and recommissioned, Dredger No 14 was named Perseverance after a competition held by the SHCS, in recognition of the those society members who had devoted so much of their time to the restoration.

Perseverance then commenced the next stage of her life, dredging the silted up end of the Basingstoke canal. The stretch she dredged ran for some 10 miles from  from King John’s Castle to Pondtail in Fleet, and this operation resulted in the final stretch of the canal being declared fully navigable in 1993. Perseverance is now registered as part of the National Historic Fleet and is currently stored in a dismantled state at the Ellesmere Port facility of the Canal and River Trust.

Perseverance Herself and the Basingstoke Canal

So what on earth was this leviathan? Basically she was a 70 foot long by 7 ft beam rectangular hull, which was fitted with a pair of pontoons which increased the beam to 13 ft 9 ins. Weight was around 70 tons and there was a steam driven crane mounted forward, supplied from a boiler mounted down in the hull in an enclosed boiler room. Steam operated engines to raise and lower the jib, slew the crane and operate the formidable steam grab.

The crane was, in typical 1930s style, an ergonomic disaster with a myriad of unmarked levers and pedals and exposed gears, rods, cranks, wheels and cables whizzing around which would probably have a modern health and safety inspector running for the hills but certainly added to the dredger’s character! The operation of the crane was also magnificent, with clouds of steam enveloping the dredger and anyone close as the grab was plunged into the canal, closed, then lifted with its huge load of sediment which was swung round with water pouring out and into the canal and dumped into the mud barge tied alongside, all the time emitting clouds of steam and accompanied by a soundtrack of hisses, creaks, groans, whirring and clanking.

Watch (and hear!) the Dredger in action (51s)

Truly the operation of the dredge was spectacular and would attract spectators to the towpath like a magnet. Perseverance’s steam engine did not stretch to powering the vessel; she had to be towed to where she was going to work, and then a pair of steel cables was set up linking convenient canal-side trees to a pair of hand cranked winches on the dredger. All this activity was in stark contrast to the usually quiet and tranquil environs of the towpath!

Loaded barges would be pushed to the nearest dump site using little diesel powered ‘Bantam’ work boats built in the 1950s, where the spoil was offloaded by an ancient tracked dragline crane on the towpath. Perseverance was well named, as dredging started in May 1975, and as the operation was manned by volunteers the dredger was run at the weekend throughout the year, and the task eventually finished in 1993 after some 18 years. Once the dredger was up and running and everything set up, dredging could start. One grab would pick up about a ton of silt, and a shift would result in some 400 tons of silt being lifted. After an arc of silt had been lifted, the hand cranked winches were used to pull Perseverance forwards by the width of the grab so the next arc of silt could be removed.

It was calculated that Perseverance had extracted about 125,000 tons of silt between 1973 and 1983, and a quick estimate shows that in her 18 year stint, ending in 1993, Perseverance would have extracted about a quarter of a million tons of silt from the canal. Perseverance was manned entirely by volunteers, and required a crew of at least two – a crane man to operate the grab, and a fireman to keep the boiler going. Many other volunteers were needed to support the operation of the dredger, operating the dragline winches, supplying coal and wood to feed the boiler, operating the Bantams that shifted the mud barges, running the dragline crane at the dump sites and generally assisting in keeping the operation running.

Perseverance’s legacy is of course the canal as we know it today, a marvellous resource for the community to enjoy, a sight of special scientific interest due to its rich and diverse flora and fauna and a haven of peace and tranquillity. All made possible by an ancient, obsolete, uneconomical, cantankerous old dredger and of course the volunteer crew who restored, maintained and operated her and made today’s canal a reality.

More about the Basingstoke Canal restoration

Perseverance – Dredging the Basingstoke Canal by Roger Cansdale – Canal Society booklet, obtainable here.

Dredging Operations on the Basingstoke Canal 1993 (35m):

Perseverance Dredger being removed at Reading Road, Fleet, 1993 (including Meridian TV item, 24m).

The Perseverance hull at Ellesmere Port today

Specification:

Hull:

Length: 70 ft (21.3 m)

Overall beam: 13 ft 10 in (4.2 m) (This was made up of the central 7 ft wide hull and the two pontoons. Perseverance was never used without these for stability reasons, but they could be removed to allow it to pass through standard narrow locks.)

Dredging depth: 4 ft 6 ins (1.4 m)

Draught: 3 ft 9 ins (1.1 m)

Crane:

Builder:           Graftons of Bedford

Identity           Crane no 2473

Capacity:         2 tons at 21 ft,  3 tons at 16 ft

Dredging:        2/3 cubic yard steam grab (used for heavy work)

Single Chain ring grab (used for speed)

Steam Engine:

Boiler: 12 NHP Loco Type built by Marshall. Works at 120 lb/sq in

Fuel Consumption: Approx 5 cwt (560 lb / 255 kg) of coal per hour. Could also run on wood.

 

 

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